1. Field of the Invention
The present invention relates to a card-type IC-mounting board and more particularly to a card-type board such as a credit card incorporating IC elements including a microprocessor.
2. Description of the Related Art
Particularly in the area of external memory media of small computer apparatuses, IC-mounting cards called memory cards such as ROM cards and RAM cards have been widely placed in commercial use. Those memory cards have only a memory function. On the other hand, IC cards having CPU function have been developed and studies are under way for the application to cash cards and credit cards issued by financial institutions, and also to the use for ID cards (See "Nikkei Electronics" published by Nikkei BP, Sep. 18, 1989, No. 482, pp 119-141, for example).
However, the conventional IC cards have been made of ICs (LSIs) designed individually for respective uses and functions. For this reason, these IC cards in fact are not applicable to general purpose, resulting in high unit price.
For instance, if an attempt is made to apply a given IC card to different use, it is necessary to do again the whole circuit design, and work out a new IC suitable for the new use. In other words, conventional IC cards need to be produced by a specific production line arranged for an IC chip production process selected for a specific application. Therefore, its mass-productivity is relatively low and as a result, it involves a high production cost.